What is the primary function of a transmission substation?
A To step up voltage for long-distance transmission
B To step down voltage for local distribution
C To store energy for peak demand
D To improve power factor
Transmission substations step up voltage to reduce power losses during long-distance transmission, ensuring efficient energy delivery.
What is the typical purpose of a distribution substation?
A To transmit electricity across regions
B To step down voltage for residential and commercial use
C To regulate frequency
D To increase fault currents
Distribution substations reduce high voltage from transmission lines to levels suitable for safe delivery to consumers.
Which substation component protects equipment from voltage surges caused by lightning?
A Circuit breaker
B Lightning arrester
C Transformer
D Capacitor bank
Lightning arresters divert excess voltage from lightning strikes to the ground, preventing damage to equipment.
What is the purpose of substation maintenance?
A To store reactive power
B To ensure reliable operation and prevent equipment failure
C To reduce voltage levels
D To disconnect faulty circuits
Maintenance involves regular inspections and servicing to identify and fix potential issues, ensuring reliability and extending equipment life.
What does “fault isolation” mean in a substation?
A Disconnecting faulted sections while maintaining power supply to healthy areas
B Disconnecting the entire system during a fault
C Increasing voltage levels during a fault
D Reducing reactive power during a fault
Fault isolation prevents the spread of faults and ensures the rest of the system remains operational.
What is a sectionalized busbar system?
A A busbar that operates at high voltage
B A busbar divided into sections for reliability and flexibility
C A busbar designed for renewable energy substations
D A busbar with automatic grounding systems
Sectionalized busbars allow sections to operate independently, improving system reliability and enabling maintenance without complete shutdown.
What is the role of a relay in a substation?
A To regulate voltage levels
B To detect faults and signal circuit breakers
C To measure reactive power
D To step up current flow
Relays are protective devices that detect abnormal conditions and activate circuit breakers to isolate faulty sections, protecting the system from damage.
What is the function of a capacitor bank in a substation?
A To step down voltage levels
B To provide reactive power and improve power factor
C To measure current flow
D To isolate faults
Capacitor banks supply reactive power, improving the power factor and maintaining voltage stability within the system.
What is the purpose of routine maintenance in a substation?
A To step up voltage levels
B To prevent equipment failures and ensure smooth operation
C To monitor power flow
D To reduce insulation strength
Routine maintenance identifies and resolves potential issues early, ensuring the substation operates efficiently and reliably.
What is the role of tap changers in transformers?
A To adjust transformer winding to regulate voltage
B To store electrical energy
C To step down current flow
D To provide reactive power
Tap changers are used to adjust the winding of transformers to regulate voltage levels under varying load conditions.
What is a dielectric strength test used for in substations?
A To measure current flow
B To determine the insulation’s ability to withstand high voltages
C To regulate voltage levels
D To improve power factor
Dielectric strength tests assess whether substation insulation can endure normal operating and fault conditions without breaking down.
What is the purpose of substation fault isolation?
A To disconnect faulty sections while maintaining power to healthy parts of the system
B To disconnect the entire system during a fault
C To increase power factor
D To store electrical energy
Fault isolation prevents the spread of faults and ensures that the unaffected parts of the system can continue operating.
What is a power transformer used for in a transmission substation?
A To step up voltage levels for long-distance transmission
B To store electrical energy
C To measure power flow
D To isolate faulty sections
Power transformers step up voltage to minimize power losses during long-distance transmission, enabling efficient energy transfer.
What is the main advantage of sectionalized busbars in substations?
A They reduce power losses significantly
B They allow parts of the busbar to operate independently, improving reliability
C They integrate renewable energy sources directly
D They eliminate the need for circuit breakers
Sectionalized busbars enhance system reliability by allowing maintenance or fault isolation on one section without affecting the entire substation.
What is the typical voltage range for high-voltage substations?
A Below 33 kV
B 110 kV to 765 kV
C 11 kV to 33 kV
D Above 1000 kV
High-voltage substations typically handle voltages between 110 kV and 765 kV to enable efficient long-distance transmission.
What is the purpose of a high-voltage circuit breaker?
A To step up voltage levels
B To interrupt large fault currents
C To measure power flow
D To provide reactive power
High-voltage circuit breakers are designed to interrupt fault currents quickly and safely, protecting the system from damage.
What is the main advantage of compact substations?
A Lower cost
B Smaller size and suitability for urban areas
C Higher voltage handling capacity
D Easier maintenance
Compact substations are designed to take up minimal space, making them ideal for urban environments or areas with limited land availability.
What is the function of a tap changer in transformers?
A To adjust transformer winding to regulate voltage
B To store electrical energy
C To step down current flow
D To provide reactive power
Tap changers are used in transformers to regulate voltage levels by adjusting the winding configuration based on load changes.
What is the typical voltage range for high-voltage substations?
A Below 33 kV
B 110 kV to 765 kV
C 11 kV to 33 kV
D Above 1000 kV
High-voltage substations typically handle voltages between 110 kV and 765 kV for efficient long-distance power transmission.
What is the role of an isolator in a substation?
A To interrupt fault currents
B To disconnect equipment for maintenance under no-load conditions
C To regulate voltage
D To store electrical energy
Isolators are manually operated devices that disconnect sections of the system for maintenance, ensuring safety when the equipment is not under load.